<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>GridLayout</title>
  <style>
    body {
      color: #fff;
      text-align: center;
    }
    #content {
      display: grid;
      grid-template-columns: 33.3% 33.3% 33.3%;
      max-width: 960px;
      margin: 0 auto;
    }
    #content div {
      background: lightgrey;
      padding: 30px;
    }
    #content div:nth-child(even) {
      background: skyblue;
    }
  </style>
</head>

<body>
  <div id="content">
    <div>1</div>
    <div>2</div>
    <div>3</div>
    <div>4</div>
    <div>5</div>
    <div>6</div>
    <div>7</div>
    <div>8</div>
    <div>9</div>
  </div>
</body>

</html>